An object of the present disclosure is to provide a method for producing a fluorinated organic compound, the method being capable of removing a sulfur-containing substance to a high degree, or provide a composition containing a fluorinated organic compound with a low content of a sulfur-containing substance. The present disclosure relates to a method for producing a fluorinated organic compound (pf), the method comprising:



[A] reaction step A of fluorinating an organic sulfur compound (ss) with a fluorinating agent to obtain a composition (α) containing a fluorinated organic compound (pf); and
[B] post-treatment step B of reacting the composition (α) with a nucleophile at a temperature of 40° C. or higher.